Field of the Invention
From the Siemens AG product brochure entitled "HICOM 300 `Voice Mail Service VMS`", 1995, Order No. A31002-S10-A1-7-5, a speech storage system or voice mail service (VMS) is known that is integrated into a private integrated services digital network (ISDN) switching system. The voice mail service serves to store, call up, and distribute messages in natural speech form. The users enrolled in the voice mail service are assigned a personal mailbox ("voice mailbox"). Mailbox holders can divert calls intended for them to their mailbox in their absence, and the messages forwarded with the calls are then stored in the mailbox.
By dialing his mailbox, the enrolled user can listen to the stored messages any time, anywhere. An acoustic user guide facilities the use of the voice mail service. For example, using the voice mail service is done with the aid of frequency tones, which can be activated via the keypad of a terminal device, by the multi-frequency selection method (MFSM).
Once a stored message has been listened to, it can be erased, stored, or processed. For instance, a question from a party who has left a spoken message can be answered directly in the mailbox of the inquiring party. Once a message has been listened to, a telephone connection with that party can also be made, without having to enter his telephone number (callback).
From Published, British Patent Application GB 2 290 920 A, for instance, a voice mail service in a telecommunications system is known in which by way of a conference connection, a connection can be made between a terminal device of a mailbox holder, a terminal device of a calling party, and the mailbox of the mailbox holder. Without the knowledge of the calling party, the mailbox holder can listen in while the message sent by that party is being recorded in the mailbox. At the instigation of the mailbox holder, the recording can be stopped, and the connection between the terminal device of the calling party and the mailbox can be broken and replaced by a direct connection between the terminal device of the mailbox holder and the terminal device of the calling party.
From Published, European Patent Application EP 0 685 957 A, a method for storing voice messages in a telecommunications system is also known. Here, in cases where no connection route to a voice mail service is available when a calling party calls, and the calling party activates an automatic redial, the telephone numbers of the voice mail service and of the called party are stored in memory in the telecommunications system. When a connection route becomes available, the telephone number of the called party is carried on to the voice mail service, which thereupon connects the calling party to the mailbox of the called party.
With the increasing use of voice mail services ("voice mail"), the number of messages to be stored briefly (for instance during a meeting) or for longer periods (such as when the called party is away for several days) increases as well. It is thus important that the mailbox holder be able to run through all the stored voice messages quickly and as simply as possible.
In an unsuccessful callback, that is, when a connection has not been made between the mailbox holder and a subscriber who has left a voice message, many voice mail services allow leaving a spoken message and/or then continuing with the processing, without interruption, of the next or another spoken message along the lines of a logical "voice mail user session". Conversely, if an attempt to connect to a subscriber who has left a spoken message is successful, that is, has led to a desired two-person connection between the mailbox and the subscriber, without further participation by the voice mail service, then the connection with the voice mail service always ends when the two-person connection is terminated.
After a successful connection between the mailbox holder and the subscriber who has left a spoken message, the mailbox holder, to continue running through his messages, has to make a new connection with the voice mail service in order to continue his voice mail session with the next or some other stored message, or to continue erasing the message he has just successfully handled. Therefore, in the course of making the new connection, all the necessary identification data, and passwords if necessary, have to be input all over again.